The present invention relates to a tank structure for a header-plate-less heat exchanger in which flat tubes whose both ends protrude are stacked to improve air-tightness and liquid-tightness between a core and a tank.
As illustrated in FIGS. 7 and 8, in the header-plate-less heat exchanger, flat tubes 2 whose both ends protrude in a thickness direction are stacked at a protruding part to for a core, and thus a header plate is not required. A casing 11 is fitted onto an outer circumference of a core 3 including a stack body of the flat tubes 2, and also a tank 4 is fitted onto both ends of the core 3 and the respective parts are integrally soldered and secured to each other.
As illustrated in FIG. 1, the flat tubes 2 include a pair of an upper plate 2a and a lower plate 2b each bent in a groove shape, which are fitted into each other with groove bottoms faced to each other. Further, the casing 11 includes a casing main body 11a formed in a groove shape and an edge cap 11b for closing a space between both side walls of the casing main body 11a. Furthermore, the tank 4 is integrally molded in a cylindrical shape having a square shape in cross section by press-molding.
Background prior art includes Japanese Patent Laid-Open No. 2011-002133 and Japanese Patent Laid-Open No. 2011-232020.